Petrillo, who has worked for the Pontifical Villas for 50 years, said that the Pontifical Villas are a complex of three historic properties which have “come together little by little to form the summer residence of the Holy Father.”

The villa complex and farms cover 55 hectares, an area larger than Vatican City.

Petrillo told CNA on Aug. 4 that Castel Gandolfo has served as a papal retreat since the seventeenth century when Pope Urban VIII continued the visits he had begun as a cardinal.

Fifteen of the last 31 Popes have continued that tradition, though some pontiffs did not visit because of personal taste, health, or historical reasons, as when the Popes between Pius IX and Pius XI did not leave the Vatican because of the political situation in Italy.

The biggest of the properties was once the Roman Emperor Domitian's personal villa. His residence was over five square miles in area and included a theater.

“It was a rather small theater that had a capacity for around 400 spectators, that is to say, the emperor and his closest friends,” Petrillo said.

Pope Pius XI erected a cross in the villas “to remember the triumph of the cross over its persecutors,” he continued. “Domitian, if you remember, was a ferocious persecutor of Christians and the Pope wished to give witness to the triumph of the cross.”

Every summer, Pope Benedict XVI visits the gardens for walks and sometimes prays the rosary there.

The villas' Belvedere Gardens are divided into three tiers. The first tier has floral gardens inspired by works in the basilicas of Rome, and the second tier has four mirroring labyrinths.

“A maze like these in an Italian garden represents man’s search for knowledge,” the villa director explained.

The third tier of the gardens is a citrus garden enclosed by cypresses, where lemon and orange trees grow.

“Down below we have more mirror pools and the hedges trimmed in such a way to remind the visitor of the Roman aqueducts,” Petrillo said.

The villas also contain the Emperor Domitian’s covered passageway known as the “crypto-portico.”

The portico was once nearly 1,000 feet long, but only about 400 feet still remain. Smoke stains on the portico walls date back to World War II, another major event for Castel Gandolfo.

“When the Allied troops landed at Anzio, the Holy Father welcomed around 10,000 people who found refuge here,” Petrillo said.

“In particular, it’s quite nice to remember, in that period 50 children were born and all were born in the Pope’s room which had been transformed into a delivery room.”

Petrillo added that the villas' farm is “particularly nice,” and supplies much of what Pope Benedict eats.

“It's where we raise milk cows, hens, have vegetable gardens and a lot of olive trees for a humble production of olive oil.”

Giuseppe Bellapadrona, Director of the Pontifical Farm, said Pope Pius XI wanted a small farm to produce food “in the most organic and healthy of ways.”

The farm includes chickens and a barn of 30 milking cows for dairy production. There are also 800-year-old olive trees whose olives are used to produce “quite delicate” olive oil.